野生、池塘养殖及红树林生态养殖中华乌塘鳢成鱼的形态判别

Morphological identification of wild,pond-farm and mangrove eco-farm adult Bostrychus sinensis

【目的】比较分析3种不同来源中华乌塘鳢群体是否存在形态差异,为辨别中华乌塘鳢产品来源提供快速便捷的形态学判别方法,也为创建中华乌塘鳢红树林生态养殖品牌提供基础数据。【方法】分别测量中华乌塘鳢野生群体、红树林地埋管道生态养殖群体和池塘养殖群体的6个可量性状和20个外形框架结构数据,并采用方差分析、聚类分析、判别分析和主成分分析等方法进行多元分析。【结果】除头长/体长外,其他各项可量性状比值在各中华乌塘鳢群体间均存在明显差异。主成分分析结果显示,对第一主成分影响较大的有L9(第二背鳍起点至其末端的距离)、L13(第二背鳍末端至臀鳍起点的距离)、L14(第二背鳍末端至尾鳍背侧起点的距离)、L17(第二背鳍末端至尾鳍腹侧起点的距离)、尾柄长/体长和尾柄高/尾柄长等尾端特征值,对第二主成分影响较大的有体高/体长、L2(第一背鳍起点至腹鳍起点的距离)、L5(第二背鳍起点至臀鳍起点的距离)、L6(腹鳍起点至臀鳍起点的距离)、L7(第一背鳍起点至臀鳍起点的距离)和L8(第二背鳍起点至腹鳍起点的距离)等躯干特征值,对第三主成分影响较大的有L11(臀鳍起点至其末端的距离)、L12(第二背鳍起点至臀鳍末端的距离)、L16(臀鳍末端至尾鳍腹侧起点的距离)和L18(臀鳍末端至尾鳍背侧起点的距离)等体后端特征值。野生、生态养殖和池塘养殖中华乌塘鳢群体可通过判别函数进行有效区分,其综合判别正确率为93.1%。聚类分析结果显示,野生群体与生态养殖群体先聚为一支,再与池塘养殖群体相聚,即中华乌塘鳢生态养殖群体与野生群体的形态较相近。【结论】中华乌塘鳢野生群体、红树林地埋管道生态养殖群体和池塘养殖群体的形态存在明显差异,通过形态学多元分析可有效辨别。红树林地埋管道生态养殖群体的形态与野生群体更相近,食物保障和食物组成、环境理化条件等可能是引起中华乌塘鳢各群体形态差异的主要原因。

【Objective】Morphological difference among three Bostrychus sinensis populations with different sources was compared to find out a quick morphological identification method for the source of B.sinensis and provide some scientific basis for establishing mangrove eco-farm B.sinensis brand.【Method】Six measurable morphological characters and twenty truss network data of wild B.sinensis,B.sinensis cultured in mangrove underground tube system and B.sinensis raised in pond were measured and then analyzed with multivariate analysis methods,including variance analysis,cluster analysis,discriminant analysis,and principal component analysis.【Result】Difference in ratios of the measurable characters among the three populations were obvious except for the ratio of head length/body length.The results of principal component analysis showed that the first principal component was greatly influenced by the eigenvalues of tail end like L9(distance between origin of the second dorsal fin and posterior of the second dorsal fin),L13(distance between posterior of the second dorsal fin and origin of anal fin),L14(distance between posterior of the second dorsal fin and dorsal origin of caudal fin),L17(distance between posterior of the second dorsal fin and ventral origin of caudal fin),length of tail/length of body,and height of tail/length of tail.The second principal component was greatly influenced by the eigenvalues of body like height of body/length of body,L2(distance between origin of the first dorsal fin and insertion of pelvic fin),L5(distance between origin of the second dorsal fin and origin of anal fin),L6(distance between insertion of pelvic fin and origin of anal fin),L7(distance between origin of the first dorsal fin and origin of anal fin),and L8(distance between origin of the second dorsal fin and Insertion of pelvic fin).The third principal component was greatly influenced by the eigenvalues of rear end like L11(distance between origin of anal fin and posterior end of anal fin),L12(distance between origin of the second dorsal fin and posterior end of anal fin),L16(distance between posterior end of anal fin and ventral origin of caudal fin),L18(distance between posterior end of anal fin and dorsal origin of caudal fin).Morphological difference among wild,pond-farm and eco-farm B.sinensis was obvious and therefore they could be identified by using discriminant function.The comprehensive correction rate was93.1%.The result of cluster analysis showed that wild B.sinensis constituted a cluster with eco-farm B.sinensis first and then clustered with pond-farm B.sinensis,implying that wild B.sinensis was morphologically similar to eco-farm B.sinensis.【Conclusion】There are obvious differences in morphological characters of wild B.sinensis,B.sinensis cultured in mangrove underground tube system and B.sinensis raised in pond,and they can be identified by morphological multivariate analysis.B.sinensis cultured in mangrove underground tube system is more morphologically similar to wild B.sinensis.Food supply,food composition,physical and chemical condition of environment may be main reasons for morphological difference of different populations of B.sinensis.